Mid-Atlantic Antique Radio Club - MAARC

11/18/2025

Today's post provides the answers to yesterday's Electronic Measurement Quiz.

Here is some background: "The early 1960s was evidently a good time for printing quizzes in electronics magazines. Popular Electronics was no exception. Here is the latest, from the January 1963 edition, that tests basic knowledge of using analog multimeters (digital types were not around yet). All are pretty straightforward; however, be careful with question 9. At first I thought maybe it was a trick question, but the key to arriving at the correct answer is noting that you are measuring a low resistance. Be sure to consider the properties of a standard multimeter of the era. Give it a try for yourself to see how well you fare."

The questions and related figures are on the photo. So, on to the answers:

1 TRUE. If a voltmeter is rated at 20,000 ohms-per-volt, it has an input resistance of 100 times 20,000 ohms on its 100-volt scale, and 600 times 20,000 ohms on its 600-volt scale. The higher this shunting resistance is, the less it re-duces the resistance across which the voltage is measured.

2 FALSE. If the instrument does not have a transit (shorting) position, set it on its highest current range-because the meter will then be using its lowest value of shunt resistance. If the meter coil is jiggled while being moved, the volt-age it generates can produce the largest amount of damping current.

3 TRUE. Glass-and .especially plastic-meter faces will have a static charge built up on them when they are rubbed with a dry cloth. The static charges will attract the needle on the inside, and more dust on the outside. Use a cloth dampened with anti-static fluid (such as Weston's "Statnul").

4 FALSE. Use the highest current range because the ammeter pointer is least apt to "pin" against a stop. Once the current magnitude has been determined, step down to lower current scales.

5 TRUE. Meter friction due to worn bearings or dirt tends to make the needle stop too soon when it is slowing down for an indication.

6 FALSE. Most meters are of the D'Arsonval type, which responds to the average value of the signal waveform. An a.c. meter scale increases this reading by a factor of 1.11 in order to indicate r.m.s. values of sine waves. For a square wave, r.m.s. and average are the same; hence, the factor is not needed and the meter will read high.

7 TRUE. An ammeter deflects correctly when electrons enter its negative terminal and leave by its positive terminal.

8 TRUE. If the accuracy of a meter is given, for example, as 3 % of full scale deflection, it means that a reading taken anywhere on that particular range is accurate to only 3% of the total range on that scale. Therefore, if reading accuracy is what you want, select the smallest range that can indicate your reading.

9 FALSE. When determining low resistances, don't measure the voltage drop across both the unknown resistance and the ammeter. The ammeter resistance might be of the same magnitude or greater than the unknown resistance and introduce large errors.

10 TRUE. In selecting the highest voltage scale, you reduce the possibility of "pinning" the pointer against a stop. Once the voltage magnitude is determined, step down to lower voltage scales.

How did you do? Well I hope.

This quiz also serves to remind us that the voltages we measure on live vintage electronic circuits using digital voltmeters often read higher than those identified in the schematic because of the reduced loading those meter provide in comparison to the older analog meters.

11/17/2025

Sunday, Sunday, Sunday... another quiz. This one is on Electronic Measurement, and it came out in the early 1960's. Here is a little background: "Evidently, the early 1960's were a good time for printing quizzes in electronics magazines. Here is one that tests basic knowledge of using analog multimeters (digital types were not around yet). All are pretty straightforward; however, be careful with question 9. At first I thought maybe it was a trick question, but the key to arriving at the correct answer is noting that you are measuring a low resistance. Be sure to consider the properties of a standard multimeter of the era. Give it a try for yourself to see how well you fare." Remember, standard multimeters of that time had a relatively low resistance, generally 20,000 ohms or less, much lower that digital multimeters that usually show a resistance of multiple megaohms. And those analog multimeters needed extra care to keep them operating correctly.

You have to use the photo for both the specific quiz questions and related figures. Provide your answers for questions 1 - 10 as true (T) or false (F).

Remember, honorable mention goes out to the highest scorers.

11/15/2025

More catchup for today, but first a reminder. What are you doing tomorrow (Sunday) at noon? Now all the cool people I know are going to be in Rockville, MD at the Rockville Hilton Hotel viewing the MAARC presentation on "The Foundation of High Fidelity Audio" at the Capital AudioFest. Need more details? Go to the website: https://www.capitalaudiofest.com/

Also a reminder is that due to our Capital AudioFest presentation, we have moved our November monthly meeting date to 23 November. See our website, https://maarc.org/, for more details.

On 1 November we had a post on tube substitutions, to which John C Wise responded: "My rule of thumb is try to use an original tube type whenever possible, avoid modifying a radio for a different tube type. Only do the tube substitution/modification, if you absolutely got to get a radio working again and the original tubes being very expensive or very hard to find." Good advice John, particularly if you are talking about typical All American Five radios. They almost always used the same line-up of tubes, and they are readily available. I have an entire cardboard carton full of unboxed 50L6 audio driver tubes from early AA5 radios.

On 2 November we ran the "Current Name" quiz. A belated honorable mention goes out to MAARC Facebook followers John Wise and VE7DQS - Ralph for perfect scores.

On 6 November we ran a post on radios with volume controls that fixed the bias for maximum volume by having a built-in stop. This makes these volume controls 'unobtainiumly' rare. MAARC member Ed Lyon had this to say: "Regarding the volume control with built-in stop that prevents grounding the cathode and losing all bias, I have received, in the “Restore via E-mail” department, many questions about the best way to replace the volume control, since none of the common replacements have the stop. My answer is , as you noted, add 200 ohms between the ground symbol and the pot’s wiper-arm terminal. The cathode goes to the “high” end of the pot; the resistor is between the wiper-arm and B- (often chassis or ground), while the low end of the pot, can go, depending on the stage design, either to the top of the antenna coil, or to B+ via another rather high-ohmage resistor, or to both places. Increasing the volume (clockwise twist of the volume control shaft) thus not only reduces the resistance to B- (raising the stage’s gain) , but cannot remove the bias resistance completely, owing to the wiper-arm-connected 200 ohms to B-. Reducing the volume (counter-clockwise twist of the VC shaft) adds resistance in the cathode-to-B- circuit, raising the degeneration and bias voltage, which lowers the stage gain, but in some radios also partially shorts-to-B- (RF ground) the antenna connection to the radio.

Incidentally there was an Emerson radio that came out just as AVC was declared the latest radio craze, and the Emerson radio didn’t have AVC, but, instead, used the above-described volume control. Mr. Abrams came through the design room and said something about not keeping up with the technology, so the same radio came out later that season, this time with AVC added. Unfortunately the hurried addition of the new (but becoming commonplace) AVC circuit (d-c feedback from second detector to Front-end (first detector) grid return) proved to be bad news, in that this newer model still used the volume control just described here. So here was the radio user trying to raise the volume, with the AVC reducing the volume all in the first stage of the receiver. And the user trying to lower the volume had the AVC undoing what the operator tried to do. The cure was to come out with a third model, same basic receiver, but with an All American Five AVC plus the usual after-second-detector audio volume control, just like any AA5. I think that was a tidbit in Radio Age a few years back."

Thank you for that Ed. Sometimes, we have to learn from our mistakes, as was the case for Emerson and this model. And it is no wonder that so many of the schematics for various radios never seem to exactly match your unit.

On 9 November we posted the Electronics Inventors Quiz, and wow, what a response, including some first timers. Honorable mention goes out to John Wise, VE7DQS - Ralph, John Foell, Charlie Scarborough, Dave Harris, and first time responders Brian Belanger and Bill Goodwin for perfect scores. MAARC members and followers really know their vintage electronics history, as proven by Stan Modjesky Monday answers comment: "Funny thing about this quiz is that what's shown on the scope in figure G barely qualifies as a Lissajous figure. It's certainly one of the least interesting ones. Also, if the number on the device in figure F reads "2N1B2," as it appears, that wasn't a JEDEC-registered number. There was a NPN germanium 2N182 transistor in the 1950s." Thanks to all for their responses and comments.

That's it for catchup this week. Hope to see you at the Capital AudioFest.

Capital Audiofest DC Home Page

11/14/2025

Time for more catchup.

On 31 October we had a post on reformatting electrolytics which got a few comments. MAARC Facebook follower Stan Modjesky stated: "I've never understood why anyone would find this worth the time and risk," to which MAARC Facebook follower John C Wise responded "Sometimes it is worth the risk, but your right most of the time you should just replace E. caps. with new ones which are made more reliable." John went on to say "I have done reforming of old electrolytic capacitors by using as little charging current as possible. And found out during the reforming process if the condition of the capacitor is a good one it will charge up to full rated voltage easily and stay cool, like a new cap would. But if it is not making it to full rated voltage, I try increasing the charging current a little at a time and if the capacitor starts to feel it's warming up, you have a capacitor that is too leaky to use. Reforming can be a waste of time and an old capacitor is a risk factor for it likely can fail at any time (even if the reforming went ok). The older the capacitor, used or NOS, the more I would not trust it. BTW: test your caps for ESR, the lower the series impedance, Ohms, the better, If it reformed and has high ESR, compared to a new one, cap is no good."

So, you ask, what is ESR? A capacitor's Equivalent Series Resistance (ESR) is the internal resistance that appears in series with an ideal capacitor in a real-world component model. It is a parasitic, non-ideal characteristic that represents all the energy loss mechanisms within the capacitor as a single resistive value. ESR is a combination of several resistive losses in the physical construction of the capacitor, that include Ohmic resistance of the metal terminals, electrodes (plates), and internal wiring, Resistance of the electrolyte (in electrolytic capacitors) or the dielectric material itself, and Dielectric losses from the polarization and relaxation of the insulating material.

So, how do you test for ESR? Well, you do that with an ESR meter (see photo). I picked up this LCR-T4-Plus tester from Amazon a few years back. They currently have one listed for ~ $14. I ran a test on this random multi-unit electrolytic can using the ESR meter. It identified the 250 uF section as a capacitor, with a value of 231.5 uF (well within 20%) with an ESR of 2.1 ohms. Not having an equivalent 250 uF cap, I tested a newer 220 uF electrolytic. It measured closer to my 250 uF cap at 260.2 uF, (still within 20% of the 220 uF value), but with a much lower ESR of .47 ohms (see photo).

What else are these multi-function testers good for? How about identifying what a part may be. Is it a resister, a capacitor, or an inductor? Well, it correctly identified this black component as a .022mH inductor (see photo). How about transistors. It identified this 2N1520 power transistor as a PNP with an hFE=75 and Uf=22mV (see photo). Yes, a very useful device.

On the subject of electrolytic capacitors, longtime MAARC member and past president Ed Lyon had this to say: "I re-form all new electrolytics and those that have shown no bad symptoms, such as are located in good communications equipment. There, I refer to an SP-600 Hammarlund receiver or a Racal RA-17 receiver as examples. Those example sets require very simple application of B+ from an external supply like a bench power supply. That way I can see how much B+ current is being drawn before committing the power transformer to full load, and possibly aggravated by a leaky or shorted electrolytic.

I am currently helping a restorer with a restoration job via phone and e-mail, and a simple rule for powering up a good radio (like a typical Zenith 12-tuber) is to apply power via a Variac and voltmeter. Bring the Variac up to 12.00 volts a-c and switch-on the radio chassis, and then read all the various voltages coming out of the power transformer. They should all be exactly one-tenth of what are called for in the data for that radio. There will not be any B+ voltage yet, but all the a-c loads except B+ draw, on the power line are there and are checked at once, and there’s no calculations or Ohm’s laws to give you pause. All the a-c voltages should be checked, including each of the heaters and filaments and B-supply input voltages. A bench all-purpose power supply is also good to have, to do the next step, which is to apply increasing B+ to the set after the filament/heater/B winding, etc., have been checked OK. To do that B+ load test, you can unplug the rectifier tube and attach the B+ bench supply to the rectifier cathode terminal WRT the B- point. Careful, now, because that point is often intended to be the max negative bias, not B-, whereas B- is at some less negative point in the voltage divider. This is also the chance to re-form the set’s electrolytics, if they seem to have been replaced in the near past. If they are originals, they are certainly bad and need replacement right from the start. Re-forming is simple. Apply the bench B+ supply via a 25K power resistor, watching the current draw. All tubes should be pulled out of their sockets for the reforming task if the capacitors are in-place in the set when you do the reforming.

Reform current should never exceed 20 milliamps, except for the initial surge, which can go to 40 ma for not to exceed 10 seconds. Sustained high current is a sign that the capacitor is not willing to reform."

When asked about his findings about new electrolytic capacitors, Ed went on to say: "You might be referring to my opinion on Chinese electrolytics. Many of them are built with limited life, and are intended to blow off the printed circuit board when they are at end of life. This is especially true of those used in modern replacements for furnace controllers, refrigerators, and air-conditioner controllers, etc. They often blow cleanly off the board, but sometimes split and spill their innards over the board. I have lost three furnace controllers, and one main chassis in the outdoor half of a Japanese-made air conditioner due to blown electrolytics I also lost power in a Hewlett-Packard spectrum analyzer (list price 22000 dollars in 1985) due to blown electrolytics made in China." May the buyer beware.

Enough for today. More catchup tomorrow. Oh, and let's hear your comments on electrolytics. Maybe where you find good ones.

11/13/2025

It's catchup time, and we have a good bit to catch up on.

Back on October 25th, we covered part 2 on substituting solid state devices for vacuum tubes. Long time MAARC member Robert Lozier, who is a true vintage electronics historian, had this to say: "Since this is an old article, I'm guessing that there are now surface mount parts that might make the project easier to fab. Wonder if there any threads on solid state replacements on https://antiqueradios.com/forums/, https://www.vintage-radio.net/forum/, threads on https://www.radiomuseum.org/, etc. Gets me wondering about UV-199 and UX-199 adaptations."

Finding a working 199 tubes is getting harder and harder, so understand his thoughts on producing a solid state unit for those tubes.

MAARC Facebook follower Richard Hebert had this to say: "A tube radio is a tube radio. Would you change tubes in an Altec or McIntosh for semiconductors ? Of course no, Same for any tube device. Specially old radios. They're meant to use tubes and keeping them original is the goal."

I tend to think along those lines as well. I do find the engineering involved in prototyping solid state replacements for vacuum tubes to be interesting and educational, but not the path I want to follow.

On 26 October we posted the Menu Quiz. MAARC Facebook follower John Wise stated: "Never heard of Prune, Honey or Pie describing electronic devices, before; they were guess work." Well, he gets honorable mention for getting 8 out of 10 correct. He also commented this about the acorn tube: "I have few of those old Acorn vacuum tubes and an early 1940's UHF (actually VHF 27-143 MHz) Hallicrafters S-36A receiver that has three Acorn tubes 956 for R.F., 955 for L.O. and 954 for frequency changer. Plus I have a Pace Tube Tester that can check Acorns." Now, if you want to know more about acorn tubes, check out the MAARC presentation on that exact subject at this link:https://maarc.org/wp-content/uploads/simple-file-list/Monthly_Mtg_Presentations/Acorn-Tubes.pdf

On October 28th, the post was all about the Atwater Kent model 84 I added to my radio collection. John C Wise posted this comment: "Very nice restoration work to the cabinet. Looking at the schematic, even though it's a 6 tube set, the circuit is basically a typical 5 tube radio (AA5), 6th tube is local oscillator. Plus it has an AM plate detector a 24/24A tetrode. (see photo)" MAARC Facebook follower Bryan Gadow posted this: "Funny, I thought something looked familiar about that set! (see photos)."

On 30 October we had a post on magic eye tubes and replacing the failed 1 meg resistor. MAARC past president and longtime radio collector Geoff Shearer had this to say: "Years ago when I started fixing radios, I found the least desirable fix was that 1 meg resistor between pins 2 and 4 in the "eye tube" socket. Invariably, when you try to pry off the cover to get to them, it snaps and then you have to deal with those rampant wires coming out of the socket and trying to figure which one goes where when the re-assembly occurs, is a pain. Here's what I learned: have extra socket covers available if you break the one you're working on (I don't know where I got them but I have 6 and one is marked for a 6U5). Gently pry off the cover. Hold all the wires tight against the socket and then gently slide the wires for 2 and 4 forward so they're exposed from the socket. Now, lock down the wires close to the socket with a tool in the photo ( picked it up at Restore). Now you can change the resistor without all the wires coming out."

Good tip Geoff. And as a side comment, I find buying box lots of parts at MAARC auctions for under $5 to be an excellent form of entertainment. Way cheaper than renting a movie on Netflix (keeping me busy for at least that long sorting through it all) and adding things (like magic eye tube socket covers) to my inventory of necessary (somewhat questionable) parts for future use.

MAARC Facebook follower David Koster provided me an idea for use next October on how to reduce my vacuum tube inventory (see photo). Can we bake them in a pie for Thanksgiving? 😁

Enough for now. More catchup tomorrow.

Comments? Let's hear them!

11/13/2025

We are all set up for the Capital AudioFest, running this coming Friday through Sunday at the Hilton hotel in Rockville, MD. Come by and check out all the audio products the industry has to offer. And stop by to say hi. We are at table H9 on the third floor, just outside the the Plaza I conference room. Visiting the show on Sunday? See our presentation on the Foundations of HiFi Audio at noon. For more details, go the the Capital AudioFest website: https://www.capitalaudiofest.com/

11/13/2025

Here is an interesting post for you radio enthusiasts of the 1920's. Did you know the wires that you use to connect up those old battery operated 'farm' radios actually were supposed to follow a color scheme? This article, which comes from the July 1992 "MAARC Newsletter" was written by Ed Lyon. It is entitled: "BEFORE YOU GRAB JUST ANY WIRE" or "COLOR CODES FOR WIRES OUTSIDE THE RADIO". It has its roots from an article on radio standardization that comes from the April 1925 edition of "Radio Broadcast" magazine.

"Radio set manufacturers of the '20s were relatively strict about such things as the colors of wires hanging out of a radio. The issue was important then because the radio user had to connect and reconnect many of these wires as B-batteries were used up, as A-batteries needed charging, as new antennas and speakers were tried, or if it was necessary to reconfigure the set to drive a speaker or headphones when previously it was set up the other way around.

"Radio Broadcast" magazine was a very high quality journal of the period. It boasted not only good articles for the amateur and enthusiast, but also for the broadcast listener, and it provided high-quality advertisements and fine artwork. A "Radio Broadcast" cover design which was so popular in the mid- '20s that it was used over and over again for a year or so, found its way onto the cover of the recent book Empire of the Air (and into the video version, too). An interesting one-page article aimed at informing the radio enthusiast or repairman as to the proper color-codes for the various wires hanging out of a typical radio appeared in a 1925 issue of the journal, and is reproduced here, for our Newsletter readers.

So if you are into authentic restoration, don't forget the wires, and their colors. All of the wires shown here are cotton-covered, mostly cotton-over-rubber. The original article had the codes in actual color, which was unusual for a radio magazine of the '20s."

Well, I found that article but unfortunately, it was in black and white. I did my best to colorize it for you, and included the black and white version as well. That article had some additional narrative as to why certain colors where chosen for various applications, so here goes.

"RADIO CORDS ARE TO BE STANDARD"
A STUDY of the chart will disclose the fact that a very definite plan has been followed which is almost self -explanatory. Blue is used to designate the antenna circuit, due to the fact that the antenna is always associated with height and the blue sky. Yellow is used for the filament circuit to suggest the color at which the filaments operate. Bright red was used to designate the highest positive B battery potential, this being conventional electrical engineering practice. Maroon, a less bright red, is used to designate one of the lower voltage positive leads. Black is used for ground and in all places where another color is now required. These colors are solid colors. In the case of the low side (negative) of circuits, a tracer of the proper color to designate the circuit is used instead of a solid color. Thus, the negative side of the filament circuit uses a black cord with a yellow tracer.

Where one cord does double duty, such as when the negative B battery cord also serves as the negative A battery cord, the cotton covering is red with a yellow tracer.

While these color designations are primarily intended for connections to factory -made sets, there is nothing to prevent the builder of homemade sets adopting such a color scheme for internal wiring. Every constructor will at once recognize the value of standard color cords in connecting receivers he builds. Hours of time can be saved. As soon as these color markings are published, colored spaghetti and covered bus wire will undoubtedly make its appearance. The circuits of a set built in this way will be infinitely easier to trace than if the set was wired using wire of all one color."

So, now you know. I am not so sure these color conventions ever stuck. Maybe you can tell us whether you have seen this standardization on radios you have in your collection.

Oh, by the way, Ed was correct. Those "Radio Broadcast" magazine covers were really something, and that specific Empire of the Air theme covers were particularly cool. I have included one for you.

Have you ever worked on a vintage electronic device where all the wiring is of the same color? No fun.

Tell us about your experiences.

11/12/2025

We are only a few days out. MAARC has been invited to participate in the Capital AudioFest event, November 14 - 16, 2005, at the Twinbrook Hilton Hotel located in Rockville, MD. The event, which runs Friday ( 10:00AM - 6:00PM), Saturday (10:00AM - 6:00PM), and Sunday (10:00AM - 4:00PM), is the Washington DC/ Mid Atlantic region’s favorite high-end electronics and vinyl show. They will be presenting great music on great audio equipment ranging from modestly priced to the exotic. It features a fun, friendly, and family-oriented show, where you often see folks (over 5,000 last year) strolling from room to room listening to music, auditioning gear, and browsing the multiple bins of vinyl records, CDs, and accessories in the Atrium Marketplace. In the evenings there will be live music in the bar and special live performers.

MAARC will have a display table, H9, located on the 3rd floor hallway smack dab between the hotel's Plaza I and Regency conference rooms. Tickets to the event, which run $20 for 1 day, and $40 for all 3 days, can be purchased on-line or at the event. MAARC will be presenting a seminar on "The Foundation of High Fidelity Audio" in the Atrium Seminar Area at noon on Sunday.

So, if you are into audio, and live within the D.C. Capital region (this is the only East Coast show), come on by and say hi. For more details, go to their website: https://www.capitalaudiofest.com/, or check them out on Facebook: https://www.facebook.com/capital.audiofest.5

11/11/2025

Today's post provides the answers to Sunday's Electronics Inventors Quiz.

Most of these matches of the devices and its inventor are pretty easy for people who have been around electronics for any length of time (well, not if the length of time is only a day or two), but there are a couple that just might stump you. This "Electronics Inventors Quiz" by Robert P. Balin appeared in the November 1963 issue of Popular Electronics magazine, so you won't be challenged with knowing the inventors of the LCD or MEMS devices, but neither will you have to know who came up with the abacus or the Archimedes screw (or who's buried in Grant's tomb).

On to the quiz and the answers:

Many men, some working alone, some teaming their efforts, have invented basic devices or circuits that have advanced the art and science of electronics. In some cases, their names are still associated with their inventions. See if you can match up the electronic devices in the sketches (A-J - see photo) with the inventors (1-10 - see below) who produced them.

1 - F John Bardeen, Walter H. Brattain, and William B. Shockley invented the point-contact transistor in 1948.

2 - J Lee De Forest invented the grid Audion, the first practical three-element amplifier tube, in 1906.

3 - E Thomas A. Edison invented the cylinder phonograph, the forerunner of the modern record player, in 1877.

4 - I Michael Faraday discovered the principle of the electric motor in 1821, and of the transformer in 1831.

5 - H Benjamin Franklin invented the lightning rod in 1750.

6 - G Jules A. Lissajous first observed the combination of two waveforms now called "Lissajous figures" in 1857. The effect is often seen when using the modern oscilloscope.

7 - B Wilhelm K. Roentgen first observed the effects of "Roentgen rays," or X rays, in 1895.

8 - C Edward Weston invented the Weston cadmium cell in 1893. It is still in worldwide use as a standard of electromotive force or voltage.

9 - A Sir Charles Wheatstone first demonstrated the bridge circuit that now bears his name in 1843. It was originally devised by Samuel H. Christi in 1833.

10 - D Hidetsugu Yagi developed his directional parasitic element antenna in Japan in the early 1920·s

How did you score?

11/09/2025

What? Sunday? Yep, time for another quiz. In this case, an Electronics Inventors Quiz.

Most of these matches of the devices and its inventor are pretty easy for people who have been around electronics for any length of time (well, not if the length of time is only a day or two), but there are a couple that just might stump you. This "Electronics Inventors Quiz" appeared back in the 1960's, so you won't be challenged with knowing the inventors of the LCD or MEMS devices, but neither will you have to know who came up with the abacus or the Archimedes screw (or who's buried in Grant's tomb).

On to the quiz:

Many men, some working alone, some teaming their efforts, have invented basic devices or circuits that have advanced the art and science of electronics. In some cases, their names are still associated with their inventions. See if you can match up the electronic devices in the sketches (A-J - see photo) with the inventors (1-10 - see below) who produced them.

1) Bardeen, Brattain, Shockley _____
2) De Forest _____
3) Edison _____
4) Faraday _____
5) Franklin _____
6) Lissajous _____
7) Roentgen _____
8) Weston _____
9) Wheatstone _____
10) Yagi _____

Remember, you can't win (and get honorable mention) if you don't post your answers.